Further changes required by Servo

Cargo.lock

@@ -1170,9 +1170,8 @@ dependencies = [
 
 [[package]]
 name = "cssparser"
-version = "0.29.6"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "f93d03419cb5950ccfd3daf3ff1c7a36ace64609a1a8746d493df1ca0afde0fa"
+version = "0.30.0"
+source = "git+https://github.com/servo/rust-cssparser?rev=722b30d2f1634714befab967ecae627813fa4cf0#722b30d2f1634714befab967ecae627813fa4cf0"
 dependencies = [
  "cssparser-macros",
  "dtoa-short",
@@ -1188,12 +1187,11 @@ dependencies = [
 
 [[package]]
 name = "cssparser-macros"
-version = "0.6.1"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "13b588ba4ac1a99f7f2964d24b3d896ddc6bf847ee3855dbd4366f058cfcd331"
+version = "0.6.0"
+source = "git+https://github.com/servo/rust-cssparser?rev=722b30d2f1634714befab967ecae627813fa4cf0#722b30d2f1634714befab967ecae627813fa4cf0"
 dependencies = [
  "quote",
- "syn 2.0.38",
+ "syn 1.0.103",
 ]
 
 [[package]]

Cargo.toml

@@ -27,7 +27,7 @@ compositing_traits = { path = "components/shared/compositing" }
 content-security-policy = { version = "0.5", features = ["serde"] }
 cookie = "0.12"
 crossbeam-channel = "0.5"
-cssparser = "0.29"
+cssparser = { version = "0.30", git = "https://github.com/servo/rust-cssparser", rev = "722b30d2f1634714befab967ecae627813fa4cf0" }
 darling = { version = "0.14", default-features = false }
 data-url = "0.1.0"
 devtools_traits = { path = "components/shared/devtools" }

components/canvas/raqote_backend.rs

@@ -855,10 +855,37 @@ pub trait ToRaqoteGradientStop {
     fn to_raqote(&self) -> raqote::GradientStop;
 }
 
+/// Clamp a 0..1 number to a 0..255 range to u8.
+///
+/// Whilst scaling by 256 and flooring would provide
+/// an equal distribution of integers to percentage inputs,
+/// this is not what Gecko does so we instead multiply by 255
+/// and round (adding 0.5 and flooring is equivalent to rounding)
+///
+/// Chrome does something similar for the alpha value, but not
+/// the rgb values.
+///
+/// See <https://bugzilla.mozilla.org/show_bug.cgi?id=1340484>
+///
+/// Clamping to 256 and rounding after would let 1.0 map to 256, and
+/// `256.0_f32 as u8` is undefined behavior:
+///
+/// <https://github.com/rust-lang/rust/issues/10184>
+#[inline]
+pub fn clamp_unit_f32(val: f32) -> u8 {
+    clamp_floor_256_f32(val * 255.)
+}
+
+/// Round and clamp a single number to a u8.
+#[inline]
+pub fn clamp_floor_256_f32(val: f32) -> u8 {
+    val.round().clamp(0., 255.) as u8
+}
+
 impl ToRaqoteGradientStop for CanvasGradientStop {
     fn to_raqote(&self) -> raqote::GradientStop {
         let color = raqote::Color::new(
-            self.color.alpha,
+            clamp_unit_f32(self.color.alpha),
             self.color.red,
             self.color.green,
             self.color.blue,
@@ -875,7 +902,7 @@ impl<'a> ToRaqotePattern<'_> for FillOrStrokeStyle {
 
         match self {
             Color(color) => Some(Pattern::Color(
-                color.alpha,
+                clamp_unit_f32(color.alpha),
                 color.red,
                 color.green,
                 color.blue,
@@ -933,7 +960,12 @@ impl ToRaqoteStyle for RGBA {
     type Target = raqote::SolidSource;
 
     fn to_raqote_style(self) -> Self::Target {
-        raqote::SolidSource::from_unpremultiplied_argb(self.alpha, self.red, self.green, self.blue)
+        raqote::SolidSource::from_unpremultiplied_argb(
+            clamp_unit_f32(self.alpha),
+            self.red,
+            self.green,
+            self.blue,
+        )
     }
 }
 

components/layout_2020/display_list/mod.rs

@@ -553,7 +553,7 @@ impl<'a> BuilderForBoxFragment<'a> {
         let style = &self.fragment.style;
         let b = style.get_background();
         let background_color = style.resolve_color(b.background_color.clone());
-        if background_color.alpha > 0 {
+        if background_color.alpha > 0.0 {
             // https://drafts.csswg.org/css-backgrounds/#background-color
             // “The background color is clipped according to the background-clip
             //  value associated with the bottom-most background image layer.”

components/layout_2020/display_list/stacking_context.rs

@@ -505,7 +505,7 @@ impl StackingContext {
             .to_webrender();
 
         let background_color = style.resolve_color(style.get_background().background_color.clone());
-        if background_color.alpha > 0 {
+        if background_color.alpha > 0.0 {
             let common = builder.common_properties(painting_area, &style);
             let color = super::rgba(background_color);
             builder

components/layout_2020/style_ext.rs

@@ -472,7 +472,7 @@ impl ComputedValuesExt for ComputedValues {
     fn background_is_transparent(&self) -> bool {
         let background = self.get_background();
         let color = self.resolve_color(background.background_color.clone());
-        color.alpha == 0 &&
+        color.alpha == 0.0 &&
             background
                 .background_image
                 .0

components/script/canvas_state.rs

@@ -12,7 +12,7 @@ use canvas_traits::canvas::{
     FillRule, LineCapStyle, LineJoinStyle, LinearGradientStyle, RadialGradientStyle,
     RepetitionStyle, TextAlign, TextBaseline,
 };
-use cssparser::{Color as CSSColor, Parser, ParserInput, RGBA};
+use cssparser::{AbsoluteColor, Color as CSSColor, Parser, ParserInput, RGBA};
 use euclid::default::{Point2D, Rect, Size2D, Transform2D};
 use euclid::vec2;
 use ipc_channel::ipc::{self, IpcSender, IpcSharedMemory};
@@ -106,7 +106,7 @@ impl CanvasContextState {
     const DEFAULT_FONT_STYLE: &'static str = "10px sans-serif";
 
     pub(crate) fn new() -> CanvasContextState {
-        let black = RGBA::new(0, 0, 0, 255);
+        let black = RGBA::new(0, 0, 0, 1.0);
         CanvasContextState {
             global_alpha: 1.0,
             global_composition: CompositionOrBlending::default(),
@@ -302,7 +302,7 @@ impl CanvasState {
         let color = CSSColor::parse(&mut parser);
         if parser.is_exhausted() {
             match color {
-                Ok(CSSColor::RGBA(rgba)) => Ok(rgba),
+                Ok(CSSColor::Absolute(AbsoluteColor::Rgba(rgba))) => Ok(rgba),
                 Ok(CSSColor::CurrentColor) => {
                     // TODO: https://github.com/whatwg/html/issues/1099
                     // Reconsider how to calculate currentColor in a display:none canvas
@@ -313,7 +313,7 @@ impl CanvasState {
                         // https://drafts.css-houdini.org/css-paint-api/#2d-rendering-context
                         // Whenever "currentColor" is used as a color in the PaintRenderingContext2D API,
                         // it is treated as opaque black.
-                        None => return Ok(RGBA::new(0, 0, 0, 255)),
+                        None => return Ok(RGBA::new(0, 0, 0, 1.0)),
                         Some(ref canvas) => &**canvas,
                     };
 
@@ -323,7 +323,7 @@ impl CanvasState {
                         Some(ref s) if canvas_element.has_css_layout_box() => {
                             Ok(s.get_inherited_text().color)
                         },
-                        _ => Ok(RGBA::new(0, 0, 0, 255)),
+                        _ => Ok(RGBA::new(0, 0, 0, 1.0)),
                     }
                 },
                 _ => Err(()),
@@ -1706,7 +1706,7 @@ pub fn parse_color(string: &str) -> Result<RGBA, ()> {
     let mut input = ParserInput::new(string);
     let mut parser = Parser::new(&mut input);
     match CSSColor::parse(&mut parser) {
-        Ok(CSSColor::RGBA(rgba)) => {
+        Ok(CSSColor::Absolute(AbsoluteColor::Rgba(rgba))) => {
             if parser.is_exhausted() {
                 Ok(rgba)
             } else {
@@ -1732,7 +1732,7 @@ where
     let green = color.green;
     let blue = color.blue;
 
-    if color.alpha == 255 {
+    if color.alpha == 1.0 {
         write!(
             dest,
             "#{:x}{:x}{:x}{:x}{:x}{:x}",

components/script/dom/canvasgradient.rs

@@ -5,7 +5,7 @@
 use canvas_traits::canvas::{
     CanvasGradientStop, FillOrStrokeStyle, LinearGradientStyle, RadialGradientStyle,
 };
-use cssparser::{Color as CSSColor, Parser, ParserInput, RGBA};
+use cssparser::{AbsoluteColor, Color as CSSColor, Parser, ParserInput, RGBA};
 use dom_struct::dom_struct;
 
 use crate::dom::bindings::cell::DomRefCell;
@@ -58,8 +58,8 @@ impl CanvasGradientMethods for CanvasGradient {
         let color = CSSColor::parse(&mut parser);
         let color = if parser.is_exhausted() {
             match color {
-                Ok(CSSColor::RGBA(rgba)) => rgba,
-                Ok(CSSColor::CurrentColor) => RGBA::new(0, 0, 0, 255),
+                Ok(CSSColor::Absolute(AbsoluteColor::Rgba(rgba))) => rgba,
+                Ok(CSSColor::CurrentColor) => RGBA::new(0, 0, 0, 1.0),
                 _ => return Err(Error::Syntax),
             }
         } else {

components/selectors/Cargo.toml

@@ -21,7 +21,7 @@ shmem = ["dep:to_shmem", "dep:to_shmem_derive"]
 
 [dependencies]
 bitflags = "1.0"
-cssparser = "0.30"
+cssparser = { workspace = true }
 derive_more = { version = "0.99", default-features = false, features = ["add", "add_assign"] }
 fxhash = "0.2"
 log = "0.4"

components/style/Cargo.toml

@@ -41,7 +41,7 @@ arrayvec = "0.7"
 atomic_refcell = "0.1"
 bitflags = "1.0"
 byteorder = "1.0"
-cssparser = "0.30"
+cssparser = { workspace = true }
 derive_more = { version = "0.99", default-features = false, features = ["add", "add_assign", "deref", "from"] }
 encoding_rs = { version = "0.8", optional = true }
 euclid = "0.22"

components/style/attr.rs

@@ -15,7 +15,7 @@ use crate::values::specified::Length;
 use crate::values::AtomString;
 use crate::{Atom, LocalName, Namespace, Prefix};
 use app_units::Au;
-use cssparser::{self, Color, RGBA};
+use cssparser::{self, AbsoluteColor, Color, RGBA};
 use euclid::num::Zero;
 use num_traits::ToPrimitive;
 use selectors::attr::AttrSelectorOperation;
@@ -419,7 +419,7 @@ pub fn parse_legacy_color(mut input: &str) -> Result<RGBA, ()> {
     }
 
     // Step 5.
-    if let Ok(Color::RGBA(rgba)) = cssparser::parse_color_keyword(input) {
+    if let Ok(Color::Absolute(AbsoluteColor::Rgba(rgba))) = cssparser::parse_color_keyword(input) {
         return Ok(rgba);
     }
 
@@ -431,7 +431,7 @@ pub fn parse_legacy_color(mut input: &str) -> Result<RGBA, ()> {
             hex(input.as_bytes()[2] as char),
             hex(input.as_bytes()[3] as char),
         ) {
-            return Ok(RGBA::new(r * 17, g * 17, b * 17, 255));
+            return Ok(RGBA::new(r * 17, g * 17, b * 17, 1.0));
         }
     }
 
@@ -504,7 +504,7 @@ pub fn parse_legacy_color(mut input: &str) -> Result<RGBA, ()> {
         hex_string(red).unwrap(),
         hex_string(green).unwrap(),
         hex_string(blue).unwrap(),
-        255,
+        1.0,
     ));
 
     fn hex(ch: char) -> Result<u8, ()> {

components/style/servo/media_queries.rs

@@ -197,12 +197,12 @@ impl Device {
 
     /// Returns the default background color.
     pub fn default_background_color(&self) -> RGBA {
-        RGBA::new(255, 255, 255, 255)
+        RGBA::new(255, 255, 255, 1.0)
     }
 
     /// Returns the default foreground color.
     pub fn default_color(&self) -> RGBA {
-        RGBA::new(0, 0, 0, 255)
+        RGBA::new(0, 0, 0, 1.0)
     }
 
     /// Returns safe area insets

components/style/values/specified/color.rs

@@ -33,6 +33,14 @@ fn allow_color_mix() -> bool {
     return false;
 }
 
+#[inline]
+fn allow_more_color_4() -> bool {
+    #[cfg(feature = "gecko")]
+    return static_prefs::pref!("layout.css.more_color_4.enabled");
+    #[cfg(feature = "servo")]
+    return false;
+}
+
 impl ColorMix {
     fn parse<'i, 't>(
         context: &ParserContext,
@@ -759,7 +767,7 @@ impl Color {
                 CSSParserColor::CurrentColor => Color::CurrentColor,
                 CSSParserColor::Absolute(absolute) => {
                     let enabled = matches!(absolute, cssparser::AbsoluteColor::Rgba(_)) ||
-                        static_prefs::pref!("layout.css.more_color_4.enabled");
+                        allow_more_color_4();
                     if !enabled {
                         return Err(input.new_custom_error(StyleParseErrorKind::UnspecifiedError));
                     }

components/style_traits/Cargo.toml

@@ -17,7 +17,7 @@ gecko = []
 [dependencies]
 app_units = "0.7"
 bitflags = "1.0"
-cssparser = "0.30"
+cssparser = { workspace = true }
 euclid = "0.22"
 lazy_static = "1"
 malloc_size_of = { path = "../malloc_size_of" }

tests/unit/style/animated_properties.rs

@@ -26,8 +26,8 @@ fn test_rgba_color_interepolation_preserves_transparent() {
 #[test]
 fn test_rgba_color_interepolation_alpha() {
     assert_eq!(
-        interpolate_rgba(RGBA::new(200, 0, 0, 100), RGBA::new(0, 200, 0, 200), 0.5),
-        RGBA::new(67, 133, 0, 150)
+        interpolate_rgba(RGBA::new(200, 0, 0, 0.4), RGBA::new(0, 200, 0, 0.8), 0.5),
+        RGBA::new(67, 133, 0, 0.6)
     );
 }
 
@@ -41,7 +41,7 @@ fn test_rgba_color_interepolation_out_of_range_1() {
             RGBA::from_floats(0.0, 1.0, 0.0, 0.6),
             -0.5
         ),
-        RGBA::new(154, 0, 0, 77)
+        RGBA::new(154, 0, 0, 0.3)
     );
 }
 
@@ -53,7 +53,7 @@ fn test_rgba_color_interepolation_out_of_range_2() {
             RGBA::from_floats(0.0, 0.3, 0.0, 0.4),
             1.5
         ),
-        RGBA::new(0, 154, 0, 77)
+        RGBA::new(0, 154, 0, 0.3)
     );
 }